<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        html,body{
            width: 100%;
            height: 100%;
        }

        body{
           background-color: pink;
           display: flex;
           flex-direction: row;
           align-items: center;
           justify-content: center; 
        }
        .heart{
            width: 100px;
            height: 100px;
            background-color: red;
            position: relative;
            transform: rotate(45deg);
           animation: heartBit 1s alternate infinite;
           box-shadow: 0 0 20px red;
        }
        .heart::before{
           content: "";
           width: 100px;
           height: 50px;
           background-color: red; 
           position:absolute;
           left: 0px;
           top: -49px;
           border-radius: 50px 50px 0 0;
           box-shadow: 0 0 20px red;
        }
        .heart::after{
           content: "";
           width: 50px;
           height: 100px;
           background-color: red; 
           position:absolute;
           left: -49px;
           top: 0px;
           border-radius: 50px 0 0 50px;
           box-shadow: 0 0 20px red;
        }

        @keyframes heartBit {
            0%{transform: rotate(45deg) scale(0.6);}
            100%{transform: rotate(45deg) scale(1.2);}
            
        }
    </style>
</head>
<body>
    <div class="heart"></div>
</body>
</html>